[USN-593-1] Dovecot vulnerabilities

Ubuntu Security Notice USN-593-1             March 26, 2008
dovecot vulnerabilities
CVE-2008-1199, CVE-2008-1218

Ubuntu 6.06 LTS
Ubuntu 6.10
Ubuntu 7.04
Ubuntu 7.10

Ubuntu 6.06 LTS

dovecot-common 1.0.beta3-3ubuntu5.6
dovecot-imapd 1.0.beta3-3ubuntu5.6
dovecot-pop3d 1.0.beta3-3ubuntu5.6

Ubuntu 6.10

dovecot-common 1.0.rc2-1ubuntu2.3
dovecot-imapd 1.0.rc2-1ubuntu2.3
dovecot-pop3d 1.0.rc2-1ubuntu2.3

Ubuntu 7.10

dovecot-common 1:1.0.5-1ubuntu2.2
dovecot-imapd 1:1.0.5-1ubuntu2.2
dovecot-pop3d 1:1.0.5-1ubuntu2.2

Ubuntu 7.04

dovecot-common 1.0.rc17-1ubuntu2.3
dovecot-imapd 1.0.rc17-1ubuntu2.3
dovecot-pop3d 1.0.rc17-1ubuntu2.3

After a standard system upgrade, additional dovecot configuration changes are needed. ATTENTION: Due to an unavoidable configuration update, the dovecot settings in /etc/dovecot/dovecot.conf need to be updated manually. During the update, a configuration file conflict will be shown. The default setting "mail_extra_groups = mail" should be changed to "mail_privileged_group = mail". If your local configuration uses groups other than "mail", you may need to use the new "mail_access_groups" setting as well.

It was discovered that the default configuration of dovecot could allow access to any email files with group "mail" without verifying that a user had valid rights. An attacker able to create symlinks in their mail directory could exploit this to read or delete another user's email. (CVE-2008-1199) By default, dovecot passed special characters to the underlying authentication systems. While Ubuntu releases of dovecot are not known to be vulnerable, the authentication routine was proactively improved to avoid potential future problems. (CVE-2008-1218)